Well, there is the usual binding of breasts by wrapping several strands of rope tightly around the base of the breast, but one must be careful about blood flow, et al. Breasts are a tender area and care must be taken. I don't like electicity. I do like whipping a nice pair of breasts. I use a light weight whip that won't damage the breast, just stings like hell. When she is sucking me, it is fun to use a heavier whip to lash a breasts to encourage her to do a better job
I made a little nipple torment for her. Use two spring loaded clothes pins, The pins will give her a good amount of pain, but you can add a "twist" to them. Tie a bit of drapery cord between the clothes pins, so that when the are on the nipples, the cord is tight. The pins should be so they are vertical when clamped on the nipple When you fondle one breast, the other nipple is being pulled and jerked because of you actions. To add a little more "twist", put the first pin on one nipple pointing to the ouside of the breast (sideways). WHen you put the other pin on the other nipple, install it sideways like the other one. Because the connecting cord is so short, and will cause the two pins to twist up to a vertical postion, twisting the nipple. So now you have clamps on her nipples the pull against each other becasue the connecting cord is so short, with the added element of the nipples being twisted. Now go ahead and do what you will with her, while her nipples are being tormented, by themselves, while you are busy else where. Make sure you bind her wrists behind her so she cannot interfere with the pins. Finally, after you have the twisting pin installed, then tie a rope around the base of each breast, adding to the torment. Good Luck!
Sir James